The prior art for transporting heat energy relates to water systems which are used in Europe. Both rigid and coilable pipe systems have been used. Water has always been consider more efficient than air for transporting heat energy because of the high specific heat of water.
The new method is a system whereas the air is high pressure air to permit a long distance of transmission and a controlled humidity which increases the specific heat of the air and makes it more efficient.
The use of air permits one way transfer of the fluid from the source with no corrosion.
Most space heating is by air which permits using system for existing building space heating systems.
The cost of fossil fuel has increased 5 to 10 times in the past 10 years, which now makes remote waste and renewable heat sources feasible if a low cost method is available for transporting the heat energy.
This invention was approached on the basis of low cost materials and low cost methods. Non-metallic coilable pipes in sizes 3" and smaller have been used by the natural gas industry for over 15 years directly buried in city streets. These pipes have burst strengths of 500 psig at room temperature. To operate at high pressures and high temperatures at a low cost required conception of a two pressure pipe. The inner pipe or pipes are under high pressure and heat, but the outer pipe is at a lower pressure. The effect of the outer pressure on the inner pipes is to reduce the pressure on the inner pipe walls. Smaller inner pipes have a higher strength per unit cost, than big pipes.
The background of the invention was the recognition of a need and applying a technical solution.